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Chronic kidney disease (CKD) is a progressive condition that affects more than 10% of the world's population. Monitoring urine albumin-to-creatinine ratio (uACR) has become the gold standard for nephropathy diagnosis and control. The objective of the present study was to develop a simple, accurate, sensitive, and rapid point-of-care test (PoCT) device, MyACR, for uACR measurement, intended for use in community healthcare to screen for the risk and monitor the progress of CKD. Albumin and creatinine concentrations in urine samples were determined using spectrophotometric dye (tetrabromophenol blue)-binding and colorimetric Jaffe assay, respectively. Urine samples were diluted with distilled water (1:80) and mixed separately with albumin and creatinine reaction mixture. The creatinine reaction was incubated at room temperature (25 °C) for 30 min before analysis. Optical density (OD) was measured at the wavelengths of 625 nm (albumin) and 515 nm (creatinine). All calibration curves (0–60 mg/L and 0–2 mg/dL for albumin and creatinine) yielded linear relationships with correlation coefficients (R2) of >0.997. Good accuracy (% deviation of mean value (DMV) ≤ 5.42%) and precision (% coefficients of variation (CV) ≤ 12.69%) were observed from both the intra- and inter-day assays for the determination of albumin and creatinine using MyACR. The limit of quantification (LOQ) of albumin and creatinine in urine samples determined using MyACR and a laboratory spectrophotometer were 5 mg/L and 0.25 mg/dL, respectively, using 37.5 μL urine spiked samples (n = 5). The device was well-applied with clinical samples from 20 CKD patients. The median (range) of %DMV of the central (hospital) laboratory method (immune-based assay) was 3.48 (−17.05 to 21.64)%, with a high correlation coefficient (R2 > 0.98). In conclusion, MyACR showed satisfactory test performance in terms of accuracy, reproducibility, and sensitivity. Cost-effectiveness and improvement in clinical decision making need to be proven in future multisite community and home studies. [ABSTRACT FROM AUTHOR]

Background: Semiquantitative dipstick tests are utilized for albuminuria screening. Methods: In a prospective cross-sectional survey, we analyzed the diagnostic test validity of the semiquantitative colorimetric indicator-dye-based Combur9-Test® and the albumin-specific immunochromatographic assay Micral-Test® for the detection of albuminuria, the distribution of the semiquantitative measurements within the albuminuria stages according to KDIGO, and the utility for albuminuria screening compared with an albumin-to-creatinine ratio (ACR) in a walk-in population. Results: In 970 subjects, albuminuria (≥30 mg/g) was detected in 12.7% (95% CI 85.6–96.3%) with the ACR. Sensitivity was 82.9% (95% CI 75.1–89.1%) and 91.9% (95% CI 88.7–96.9%) and specificity 71.5% (95% CI 68.4–74.6%) and 17.5% (95% CI 15.0–20.2%) for the Combur9-Test® and Micral-Test®, respectively. Correct classification to KDIGO albuminuria stages A2/A3 with the Combur9-Test® was 15.4%, 51.4%, and 87.9% at cut-offs of 30, 100, and ≥300 mg/dL, and with the Micral-Test® it was 1.8%, 10.5%, and 53.6% at cut-offs of 2, 5, and 10 mg/dL, respectively. Overall, disagreement to KDIGO albuminuria was seen in 27% and 73% with the Combur9-Test® and Micral-Test®, respectively. From the total population, 62.5% and 15.3% were correctly ruled out and 2.2% and 1% were missed as false-negatives by the Combur9-Test® and Micral-Test®, respectively. Conclusion: Compared to the Combur9-Test®, the utility of the Micral-Test® is limited, because the fraction of correctly ruled out patients is small and a large proportion with a positive Micral-Test® require a subsequent ACR conformation test. [ABSTRACT FROM AUTHOR]